schmidt_2007
============

J\. W\. Schmidt, R\. M\. Gavioso, E\. F\. May and M\. R\. Moldover, "Polarizability of Helium and Gas Metrology", Phys\. Rev\. Lett\. 98, 254504 \(2007\)

`Source record <https://github.com/LupoLab/optmat/blob/main/src/optmat/data/sources/schmidt_2007.toml>`__ · :doc:`Catalogue </the-data/sources>` · :doc:`Review register </register>`

DOI: `10\.1103/PhysRevLett\.98\.254504 <https://doi.org/10.1103/PhysRevLett.98.254504>`__

**Source kind:** measurement

**Recorded technique:** Quasispherical microwave cavity resonator \(maraging steel, copper plated, radius about 4\.82 cm\) filled with helium \(99\.9999 %, trapped and gettered\) at 0\.1\-6\.3 MPa near 273\.16 K\: n^2 from the frequencies of the TM11, TE11, TM12 and TE12 triplets \(2\.7\-7\.6 GHz\) in vacuum and under pressure, corrected for the cavity's isothermal compressibility kappa\_T \(resonance ultrasound spectroscopy\) and the field penetration \(Eq\. 5\); pressure from a calibrated piston gauge; n^2\(rho\) fitted by a quadratic in density whose linear coefficient is 3\(A\_eps \+ A\_mu\) \(pp\. 1\-3\)\.

**Materials in structured entries:** He

**Dataset quantities:** molar\_refractivity

**Contents:** 2 datasets; 0 formulas.

Curation notes
--------------

The result \(abstract, pp\. 1 and 3\)\: 'A\_eps,meas = 0\.517 253 5 \(47\) cm3 mol\-1, which is equivalent to \(A\_eps,meas \- A\_eps,theory\)/A\_eps = \(\-1\.8 \+\- 9\.1\) x 1e\-6', one standard uncertainty \('The uncertainties are one standard uncertainty', p\. 1\); 9\.1 ppm combines the fit's 1\.8 ppm with the Table I components \(kappa\_T 4\.8 ppm, p\_lab 4\.3 ppm, R 1\.8 ppm, \.\.\.\)\. The quantity measured is A\_eps \+ A\_mu \(zero\-density limit, 273\.16 K\); A\_mu = 4 pi chi\_0/3 = \-0\.000 008 03 \(17\) cm^3/mol from Bruch and Weinhold \(2000\) was subtracted \(Table I\), so the measured A\_eps \+ A\_mu is 0\.5172455\(47\) \(puchalski\_2016 Table X, which uses \-0\.0000079224 and prints this sum\)\. The theoretical A\_eps compared is Lach et al\.'s 0\.517 254 19 \(10\)\. The glyphs of the parentheses are unmapped in the library's text \(validation warnings, pp\. 1\-4\); the value was checked on the pdf text and against puchalski\_2016's reproduction\.

Frequency\: the resonances are at 2\.7\-7\.6 GHz \(vacuum wavelengths 3\.9\-11 cm\); 'the experimental result for A\_eps was independent of the mode' and A\_eps\(f\)/A\_eps\(0\) \- 1 = 22\.6e\-14 \(f/GHz\)^2 \(Stone and Stejskal, p\. 3\), so the value is the static limit to 1e\-11\: stored at wavelength inf\.

Also in Table I \(inputs, not extracted\)\: B\_rho = 11\.9301\(39\) cm^3/mol \(Hurly and Mehl 2007\), dielectric virial b = \-0\.098\(04\) cm^3/mol \(Rizzo et al\. 2002; B\_eps = A\_eps b in the package's convention, not printed\), c = \-1\.34\(36\) cm^6/mol^2 \(Heller and Gelbart\), C\_rho = 112\.7\(20\) cm^6/mol^2 and D\_rho = 820\(70\) cm^9/mol^3 \(McLinden and Loesch\-Will\), R = 8\.314 472 \(15\), kappa\_T = 6\.0370\(46\)e\-12 /Pa\. Eq\. \(4\) lacks a factor 2 in front of A\_eps^2 b rho^2 \(puchalski\_2016 p\. 12\)\. Alternative reading\: R = 8\.314 487\(76\) J/\(mol K\) if theory is accepted \(p\. 4\)\.

**Recorded bibliographic identity status:** VALIDATED. This concerns identification of the source; it does not establish the scientific correctness of its contents.

Datasets
--------

schmidt\_2007/molar\_polarizability
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "molar_polarizability",
     "material": "He",
     "table": "text",
     "quantity": "molar_refractivity",
     "unit": "cm3/mol",
     "abscissa_unit": "angstrom",
     "wavelength_medium": "vacuum",
     "use": "primary",
     "uncertainty": {
       "column": true,
       "level": "1 sigma"
     }
   }

1 inline points in the source record.

pp\. 1 and 3\: measured A\_eps = 0\.517 253 5 \(47\) cm3/mol at 273\.16 K, zero\-density limit, magnetic term A\_mu = \-0\.00000803 cm3/mol subtracted; microwave \(2\.7\-7\.6 GHz\), stored as static\. Row id is the temperature\.

schmidt\_2007/lach\_2004
~~~~~~~~~~~~~~~~~~~~~~~~

.. code-block:: text

   {
     "id": "lach_2004",
     "material": "He",
     "file": "He/schmidt_2007__lach_2004.csv",
     "table": "tbl_db1498b084c8",
     "quantity": "molar_refractivity",
     "unit": "cm3/mol",
     "abscissa_unit": "angstrom",
     "wavelength_medium": "vacuum",
     "use": "reproduced",
     "reproduced_from": [
       "lach_2004"
     ],
     "uncertainty": {
       "column": true,
       "level": "not stated"
     }
   }

Table I\: the theoretical A\_eps 0\.517 254 19 \(10\) of Lach et al\. \(2004\), the value this measurement is compared with\.

Formulas
--------

No formulas are recorded.

Corrections
-----------

No dataset errata are recorded in this source record.

Formula corrections, where recorded, appear with their formulas above. Curation notes may also discuss corrections or unresolved interpretation. Consult the :doc:`review register </register>` for the checks and decisions.